#!/usr/bin/env python
# encoding: utf-8
# Copyright (c) 2009 Klaas Pieter Annema
# 
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

from datetime import datetime, timedelta

class RTMDue(object):
	
	def __init__(self, dueString):
		
		# The modifer, can be before, after, or None
		self.modifier = None;
		self.datetime = None;
		
		self.fromString(dueString)
	
	def fromString(self, due):
		
		today = datetime.today()
		due = due.strip().lower()
		
		if (due.startswith('before')):
			self.modifier = 'before'
			due = due.replace('before', '').strip()
			
		elif (due.startswith('after')):
			self.modifier = 'after'
			due = due.replace('after', '').strip()
		
		# Determine how much we need to offset from the current date
		if due == 'yesterday':
			self.datetime = today - timedelta(days=1)
		
		elif due == 'today' or due == '':
			self.datetime = today
		
		elif due == 'tomorrow':
			self.datetime = today + timedelta(days=1)
		
		else:
			
			try:								
				self.datetime = datetime.strptime(due, '%y%m%d')
					
			except ValueError, e:
				print 'date \'%s\' is not in YYMMDD format' % due